1. Field of Invention
The present invention relates to a method to produce an anti-swelling mica, and more particularly to a method to produce the anti-swelling mica in acid to decrease a production cost.
2. Description of the Related Art
A nanocomposite produced by an aluminosillicate (3Al2O3.3SiO2) such as clay minerals (montmorillonite) and a mica is a common technique. Generally, the mica is swelling, but a swelling mica is not practical. The swelling mica is only used as a packing material in semiconductor industry. Therefore how to transfer the swelling mica to an anti-swelling mica is an important objective in material industry.
To produce the anti-swelling mica, someone used a grind assistant to grind a sericite (a kind of mica) mechanically to form a sericite powder. The grind assistant can be lithium nitrate (LiNO3), sodium nitrate (NaNO3), potassium nitrate (KNO3) and rubidium nitrate (RbNO3) and the alkaline compound has alkaline ions. The sericite has potassium ions and a crystal structure. The mica has a surface area increasing after grinding the sericite to form a sericite powder. The potassium ions are out of the sericite and the alkaline ions diffuse into sericite to take place the potassium ions. According to the said research, the amount of potassium ions of the sericite is related to a specific area of the sericite. The crystal structure will be destroyed after grinding, so that the potassium ion proceeds an ion exchange step with the grind assistant. The result from the research also indicates the rubidium nitrate (RbNO3) is the best grind assistant.
R.O.C Pat. No. 460427 discloses a method about how to produce the anti-swelling mica. Generally, the inventor used the sericite powder grinding by grind assistant, lithium nitrate (LiNO3), to proceed the ion exchange step to produce the anti-swelling mica.
However, the research above both disclosed the grind assistant is neutral. Take the R.O.C patent for example, when proceeding the ion exchange step, the inventor further took a heating step having an operational temperature and a heating time. When the lithium nitrate (LiNO3) proceeds the ion exchange step, the operational temperature reaches 260° C. to 420° C. The first embodiment in the patent discloses the heating time takes 40 hours and the second embodiment discloses the heating time respectively takes 16, 40 and 96 hours. Although the method produces the anti-swelling mica, it needs too much energy and takes too much time to heat. Consequently, the method spends too much energy and money. Furthermore, the lithium nitrate (LiNO3) is expensive, which increases the production cost of the method. If there were a method to produce the anti-swelling mica without spending too many production costs, the anti-swelling mica would be much available on the market.
To overcome the shortcomings, the present invention provides a method to produce an anti-swelling mica to mitigate or obviate the aforementioned drawbacks.